Turbine shroud assembly with radially and axially biased ceramic matrix composite shroud segments

ABSTRACT

A turbine shroud assembly adapted for use with a gas turbine engine includes a shroud segment and a carrier. The shroud segment extends circumferentially partway around an axis to define a gas path boundary of the turbine shroud assembly. The carrier is configured to support the shroud segment in position radially relative to the axis.

FIELD OF THE DISCLOSURE

The present disclosure relates generally to gas turbine engines, andmore specifically to turbine shroud assemblies adapted for use in gasturbine engines.

BACKGROUND

Gas turbine engines are used to power aircraft, watercraft, powergenerators, and the like. Gas turbine engines typically include acompressor, a combustor, and a turbine. The compressor compresses airdrawn into the engine and delivers high pressure air to the combustor.In the combustor, fuel is mixed with the high pressure air and isignited. Products of the combustion reaction in the combustor aredirected into the turbine where work is extracted to drive thecompressor and, sometimes, an output shaft. Left-over products of thecombustion are exhausted out of the turbine and may provide thrust insome applications.

Compressors and turbines typically include alternating stages of staticvane assemblies and rotating wheel assemblies. The rotating wheelassemblies include disks carrying blades around their outer edges. Whenthe rotating wheel assemblies turn, tips of the blades move along bladetracks included in static shrouds that are arranged around the rotatingwheel assemblies. Such static shrouds may be coupled to an engine casethat surrounds the compressor, the combustor, and the turbine.

Some shrouds positioned in the turbine may be exposed to hightemperatures from products of the combustion reaction in the combustor.Such shrouds sometimes include components made from materials that havedifferent coefficients of thermal expansion. Due to the differingcoefficients of thermal expansion, the components of some turbineshrouds expand at different rates when exposed to combustion products.In some examples, coupling such components with traditional fastenerssuch as rivets or bolts may not allow for the differing levels ofexpansion and contraction during operation of the gas turbine engine.

SUMMARY

The present disclosure may comprise one or more of the followingfeatures and combinations thereof.

A turbine shroud assembly for use with a gas turbine engine may includea shroud segment comprising ceramic matrix composite materials, acarrier comprising metallic materials, and a retainer system. Thecarrier segment may be configured to support the shroud segment inposition radially relative to an axis.

In some embodiments, the shroud segment may include a shroud wall and afirst attachment feature. The shroud wall may extend circumferentiallypartway around the axis to define a gas path boundary of the turbineshroud assembly. The first attachment feature may extend radiallyoutward away from the shroud wall.

In some embodiments, the carrier may include a carrier segment and apin. The pin may extend axially into the carrier segment of the carrierand the first attachment feature of the shroud segment to couple theshroud segment to the carrier segment.

In some embodiments, the carrier segment may have a body and an axiallocation feature. The axial location feature may extendcircumferentially along and axially forward from the body. The axiallocation feature may engage the first attachment feature of the shroudsegment.

In some embodiments, the retainer system may include a first biasmember. The first bias member may extend circumferentially at leastpartway around the axis. The first bias member may be located axiallyforward of the first attachment feature of the shroud segment. The firstbias member may be located radially between the shroud wall and thecarrier segment so as to apply a first bias force to the shroud segment.

In some embodiments, the first bias force may be applied in a radiallyinward direction and an axial aft direction. The first bias force may beapplied in the radially inward direction to minimize radial movement ofthe shroud segment relative to the carrier. The first bias force may beapplied in the axially aft direction to axially locate the shroudsegment on the axial location feature of the carrier segment during useof the turbine shroud assembly.

In some embodiments, the body of the carrier segment may include anouter wall, a first support arm, and a second support arm. The outerwall may extend circumferentially at least partway about the axis. Thefirst support arm may extend radially inward from the outer wall. Thesecond support arm may extend radially inward from the outer wall andmay be spaced apart axially from the first support arm to define acavity. The cavity may receive the first attachment feature of theshroud segment. In some embodiments, the first bias member may belocated between the first support arm and the shroud wall.

In some embodiments, the first support arm may be formed to include anengagement surface. The engagement surface may engage the bias member tocause the bias member to urge the shroud segment both radially inwardand axially aft.

In some embodiments, the retainer system may further include a secondbias member. The second bias member may extend circumferentially atleast partway around the axis. The second bias member may be locatedradially between the shroud segment and the carrier segment so as toapply a second bias force to the shroud segment. In some embodiments,the second bias force applied by the second bias member may be only inthe radially inward direction.

In some embodiments, the shroud segment may further include a secondattachment feature. The second attachment feature may be spaced apartaxially from the first attachment feature. The second attachment featuremay extend radially outward away from the shroud wall. The pin extendaxially into the carrier segment, the first attachment feature, and thesecond attachment feature.

In some embodiments, the second bias member may be spaced axiallyforward of the first bias member and axially between the first andsecond attachment features. In some embodiments, the second bias membermay be axially aligned with one of the first attachment feature and thesecond attachment feature of the shroud segment. In some embodiments,the first bias member may be located axially between the first andsecond attachment features.

In some embodiments, the retainer system may further include a secondbias member. The second bias member may extend circumferentially atleast partway around the axis. The second bias member may be locatedradially between the shroud segment and the carrier segment so as toapply a second bias force to the shroud segment. The second bias membermay be spaced axially forward of the first bias member and axiallybetween the first and second attachment features.

In some embodiments, the retainer system may further include a secondbias member. The second bias member may extend circumferentially atleast partway around the axis. The second bias member may be spacedaxially forward of the second attachment feature of the shroud segmentand located radially between the shroud segment and the carrier segmentso as to apply a second bias force to the shroud segment in the radiallyinward direction and in the axial aft direction.

In some embodiments, the retainer system further includes a third biasmember and a fourth bias member. The third and fourth bias members mayeach extend circumferentially at least partway around the axis. Thethird bias member may be located radially between the first attachmentfeature of the shroud segment and the carrier segment so as to apply athird bias force to the shroud segment. The fourth bias member may belocated radially between the second attachment feature of the shroudsegment and the carrier segment so as to apply a fourth bias force tothe shroud segment. In some embodiments, the third and fourth biasforces may only be in the radially inward direction.

According to another aspect of the present disclosure, a turbine shroudassembly for use with a gas turbine engine may include a shroud segment,a carrier, and a retainer system. The shroud segment may include ashroud wall that extends circumferentially partway around an axis and afirst attachment feature that extends radially outward away from theshroud wall. The carrier may include a carrier segment and a pin thatextends axially into the carrier segment of the carrier and the firstattachment feature of the shroud segment to couple the shroud segment tothe carrier segment.

In some embodiments, the retainer system may include a first biasmember. The first bias member may extend circumferentially at leastpartway around the axis. The first bias member may be located radiallyand axially between the shroud segment and the carrier segment. Thefirst bias member may apply a first bias force to the shroud segment ina radially inward direction and an axially aft direction.

In some embodiments, the carrier segment may include an outer wall, afirst support arm, and a second support arm. The outer wall may extendcircumferentially at least partway about the axis. The first support armmay extend radially inward from the outer wall. The second support armmay extend radially inward from the outer wall. The second support armmay be spaced apart axially from the first support arm to define acavity that receives the first attachment feature of the shroud segment.In some embodiments, the first bias member may be located between thefirst support arm and the shroud wall.

In some embodiments, the retainer system may further include a secondbias member. The second bias member may extend circumferentially atleast partway around the axis. The second bias member may be locatedradially between the shroud segment and the carrier segment so as toapply a second bias force to the shroud segment.

In some embodiments, the shroud segment may further include a secondattachment feature. The second attachment feature may be spaced apartaxially from the first attachment feature. The second attachment featuremay extend radially outward away from the shroud wall. The pin mayextend axially into the carrier segment, the first attachment feature,and the second attachment feature. In some embodiments, the second biasmember may be spaced axially forward of the first bias member andaxially between the first and second attachment features.

In some embodiments, the shroud segment may further include a secondattachment feature. The second attachment feature may be spaced apartaxially from the first attachment feature. The second attachment featuremay extend radially outward away from the shroud wall. The pin mayextend axially into the carrier segment, the first attachment feature,and the second attachment feature.

In some embodiments, the retainer system may further include a secondbias member axially aligned with one of the first attachment feature andthe second attachment feature of the shroud segment. In someembodiments, the first bias member may be located axially between thefirst and second attachment features.

In some embodiments, the retainer system may further include a secondbias member. The second bias member may extend circumferentially atleast partway around the axis. The second bias member may be locatedradially between the shroud segment and the carrier segment so as toapply a second bias force to the shroud segment. The second bias membermay be spaced axially forward of the first bias member and axiallybetween the first and second attachment features.

In some embodiments, the retainer system may further include a secondbias member. The second bias member may extend circumferentially atleast partway around the axis. The second bias member may be spacedaxially forward of the second attachment feature of the shroud segmentand located radially between the shroud segment and the carrier segmentso as to apply a second bias force to the shroud segment in the radiallyinward direction and the axial aft direction.

According to another aspect of the present disclosure, a method mayinclude providing a shroud segment, a carrier, and a retainer system.The carrier may include a carrier segment and a pin. The retainer systemmay include a first bias member.

In some embodiments, the method may further include locating the firstbias member on a first radially-outwardly facing surface of the shroudsegment. In some embodiments, the method may further include locatingthe shroud segment adjacent to the carrier segment so that the firstbias member is located radially between the carrier segment and thefirst radially-outwardly facing surface of the shroud segment.

In some embodiments, the method may further include inserting the pinaxially into the carrier segment and the shroud segment to couple theshroud segment with the carrier segment. In some embodiments, the methodmay further include applying a first bias force to the shroud segment ina radially inward direction and an axially aft direction. The first biasforce may be applied in the radially inward direction to minimize radialmovement of the shroud segment relative to the carrier. The first biasforce may be applied in the axially aft direction to axially locate theshroud segment on an axial location feature formed on the carriersegment.

In some embodiments, the retainer system may further include a secondbias member. The method may further include locating the second biasmember on a second radially-outwardly facing surface of the shroudsegment before locating the shroud segment adjacent to the carriersegment. The second bias member may be located on the secondradially-outwardly facing surface of the shroud segment so that thesecond bias member is located radially between the carrier segment andthe second radially-outwardly facing surface once the shroud segment islocated adjacent to the carrier segment.

These and other features of the present disclosure will become moreapparent from the following description of the illustrative embodiments.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a cutaway view of a gas turbine engine that includes a fan, acompressor, a combustor, and a turbine, the turbine including rotatingwheel assemblies configured to rotate about an axis of the engine andstatic turbine vane rings configured to direct air into downstreamrotating wheel assemblies;

FIG. 2 is a section view of a portion of the gas turbine engine of FIG.1 showing the turbine further includes a turbine shroud assemblypositioned radially outward from blades of one of the rotating wheelassemblies, the turbine shroud assembly including a shroud segment thatdefines a portion of a gas path of the gas turbine engine, a carrierthat includes a carrier segment and axial pins that support the shroudsegment relative to the axis, and a retainer system having bias memberslocated radially between the shroud segment and the carrier so as toapply a bias force to the shroud segment to minimize the radial movementof the shroud segment relative to the carrier;

FIG. 3 is a perspective view of the turbine shroud assembly of FIG. 2showing the carrier is segmented and extends only partway about an axisof the gas turbine engine;

FIG. 4 is an exploded view of the turbine shroud assembly of FIG. 3showing, from top to bottom, the carrier segment, the seals, the biasmembers, the axial pins, and the shroud segment;

FIG. 5 is a detail cross-section view of the turbine shroud assembly ofFIG. 2 showing a first bias member is axially aligned with a firstattachment feature of the shroud segment and a second bias member spacedapart axially from the first bias member is axially aligned with asecond attachment feature of the shroud segment to urge the shroudsegment radially inward;

FIG. 6 is a cross-section view of the turbine shroud assembly of FIG. 3taken along line 6-6 showing the first bias member is shaped to define awave shape including a first end engaged with the shroud segment, asecond end spaced apart circumferentially from the first end and engagedwith the shroud segment, and a body that extends between the first andsecond ends and engaged with the carrier segment circumferentiallybetween the first and second ends;

FIG. 7 is a cross-section view of the turbine shroud assembly of FIG. 3taken along line 7-7 showing the second bias member has a wave shapesimilar to the first bias member and is circumferentially retainedbetween mount posts included in the second attachment feature;

FIG. 8 is a cross-section view of another embodiment of a turbine shroudassembly adapted for use with the gas turbine engine of FIG. 1 showingthe turbine shroud assembly includes a shroud segment, a carrier thatsupports the shroud segment relative to the axis, and retainer system,the retainer system including a plurality of radial bias members locatedradially between the carrier and attachment features of the shroudsegment directly outward of axial pins included in the carrier so as toapply the bias force to the shroud segment radially outward of the pins;

FIG. 9 is an exploded view of the turbine shroud assembly of FIG. 8showing the retainer system includes four bias members for the fourdifferent mount posts of the attachment features included in the shroudsegment;

FIG. 10 is a cross-section view of the turbine shroud assembly of FIG. 8showing the first attachment feature includes two mount posts spacedapart circumferentially from each other and each mount post has one biasmember located radially between the corresponding mount post and thecarrier;

FIG. 11 is a cross-section view of the turbine shroud assembly of FIG. 8showing the second attachment feature includes two mount posts spacedapart circumferentially from each other and each mount post has one biasmember located radially between the corresponding mount post and thecarrier;

FIG. 12 is a cross-section view of another embodiment of a turbineshroud assembly included in the gas turbine engine of FIG. 1 showing theturbine shroud assembly includes a shroud segment, a carrier thatsupports the shroud segment relative to the axis, and retainer systemconfigured to apply bias forces to the shroud segment, the retainersystem including bias members located radially between a shroud wall ofthe shroud segment and the carrier segment so as to apply the bias forcein both radial and axial directions;

FIG. 13 is an exploded view of the turbine shroud assembly of FIG. 12showing the bias members both extend circumferentially at least partwayabout the axis;

FIG. 14 is a cross-section view of another embodiment of a turbineshroud assembly adapted for use with the gas turbine engine of FIG. 1showing the turbine shroud assembly includes a shroud segment, a carrierthat supports the shroud segment relative to the axis, and retainersystem configured to apply bias forces to the shroud segment, theretainer system including bias members located radially between a shroudwall of the shroud segment and the carrier segment and betweenattachment features of the shroud segment and the carrier segment;

FIG. 15 is an exploded view of the turbine shroud assembly of FIG. 14showing the bias members all extend circumferentially at least partwayabout the axis and each have varying lengths;

FIG. 16 is a cross-section view of another embodiment of a turbineshroud assembly adapted for use with the gas turbine engine of FIG. 1showing the turbine shroud assembly includes a shroud segment, a carrierthat supports the shroud segment relative to the axis, and retainersystem configured to apply bias forces to the shroud segment, theretainer system including setscrews that apply a radial inward force toattachment features included in the shroud segment to urge the shroudsegment radially away from the carrier segment;

FIG. 17 is an exploded view of the turbine shroud assembly of FIG. 14showing the retainer system further includes a plug that is configuredto be located between one of the third setscrews and one of theattachment features of the shroud segment; and

FIG. 18 is a cross-section view of the turbine shroud assembly of FIG.16 showing the setscrews for the first attachment feature of the shroudsegment are spaced apart circumferentially from each other.

DETAILED DESCRIPTION OF THE DRAWINGS

For the purposes of promoting an understanding of the principles of thedisclosure, reference will now be made to a number of illustrativeembodiments illustrated in the drawings and specific language will beused to describe the same.

A turbine shroud segment 22 adapted for use with a gas turbine engine 10is shown in FIGS. 2-7 . The turbine shroud segment 22 includes a shroudsegment 24, a carrier 26, and a retainer system 28. The shroud segment24 defines a gas path 17 boundary of the gas turbine engine 10. Thecarrier 26 is configured to support the shroud segment 24 radiallyrelative to an axis 11 of the gas turbine engine 10. The retainer system28 has at least one bias member 30, illustratively two bias members 30,32 located radially between the shroud segment 24 and the carrier 26 soas to apply a bias force FR to the shroud segment 24 to locate theshroud segment 24 and minimize the radial movement of the shroud segment24 relative to the carrier 26.

The shroud segment 24 includes a shroud wall 44, a first attachmentfeature 46, and a second attachment feature 48 as shown in FIGS. 3-7 .The shroud wall 44 extends circumferentially partway around the axis 11to define the gas path 17 boundary. Each attachment feature 46, 48extends radially outward away from the shroud wall 44. The secondattachment feature 48 is spaced apart axially from the first attachmentfeature 46. In the illustrative embodiment, each of the bias members 30,32 are axially aligned with one of the attachment features 46, 48.

The carrier 26 includes a carrier segment 54 and at least one axial pin56, illustratively two pins 56, 58 as shown in FIGS. 4-7 . The pins 56,58 extend axially into the carrier segment 54 of the carrier 26 and theattachment features 46, 48 of the shroud segment 24 to couple the shroudsegment 24 to the carrier segment 54.

During use of the turbine shroud segment 22 in the gas turbine engine10, a low pressure differential may form across the shroud wall 44 ofthe shroud segment 24. The low pressure differential may allowchattering of the shroud segment 24 due to the blades 15 included in theengine 10 passing under the shroud segment 24. The passing frequency ofthe blades 15 may cause the shroud segment 24 to move relative to thecarrier 26. Other times the blades 15 may push radially outward into theshroud segment 24 during a rub event and cause the shroud segment 24 toshift relative to the carrier 26.

The bias force FR applied to the shroud segment 24 by the bias members30, 32 may overcome and/or dampen the forces applied by the blades 15passing under the shroud segment 24. The bias force FR applied by thebias members 30, 32 minimizes the radial movement of the shroud segment24 that would otherwise cause the shroud segment 24 to chatter.

The first bias member 30 is axially aligned with the first attachmentfeature 46 and the second bias member 32 is axially aligned with thesecond attachment feature 48 in the illustrative embodiment. Togetherthe bias members 30, 32 apply the bias force FR to the shroud segment 24in a radial direction to minimize the radial movement of the shroudsegment 24 relative to the carrier 26.

Each bias member 30, 32 is a wave spring in the illustrative embodiment.The wave shape of the bias members 30, 32 defines a first end 60, 61, asecond end 62, 63, and a body 64, 65 respectively as shown in FIGS. 4, 6, and 7. The first end 60, 61 is engaged with the shroud segment 24 at afirst circumferential location. The second end 62, 63 is spaced apartcircumferentially from the first end 60, 61 and engaged with the shroudsegment 24 at a second circumferential location. The body 64, 65 extendsbetween and interconnects the first end 60, 61 and the second end 62,63. The body 64, 65 engages the carrier segment 54 at a thirdcircumferential location positioned between the first and secondcircumferential locations.

In the illustrative embodiment, the first and second ends 60, 62 of thefirst bias member 30 engages a radially-outwardly facing surface 47 ofthe first attachment feature 46, while the body 64 engages aradially-inwardly facing surface 81 of the carrier segment 54.Similarly, the first and second ends 61, 63 of the second bias member 32engages a radially-outwardly facing surface 49 of the second attachmentfeature 48, while the body 65 engages the radially-inwardly facingsurface 81 of the carrier segment 54.

Each of the bias members 30, 32 urges the shroud segment 24 radiallyinward. The compression of the body 64, 65 at the third circumferentiallocation causes the first and second ends 60, 61, 62, 63 into engagementwith the radially-outwardly facing surfaces 47, 49 of the shroud segment24. The first and second ends 60, 61, 62, 63 apply the bias force FR tothe shroud segment 24 to overcome and dampen the forces applied by theblades 15 passing under the shroud segment 24.

Turning again to the gas turbine engine 10, the illustrative aerospacegas turbine engine 10 includes a fan 12, a compressor 14, a combustor16, and a turbine 18 as shown in FIG. 1 . The fan 12 is driven by theturbine 18 and provides thrust for propelling an air vehicle. Thecompressor 14 compresses and delivers air to the combustor 16. Thecombustor 16 mixes fuel with the compressed air received from thecompressor 14 and ignites the fuel. The hot, high-pressure products ofthe combustion reaction in the combustor 16 are directed into theturbine 18 to cause the turbine 18 to rotate about the axis 11 and drivethe compressor 14 and the fan 12.

The turbine 18 includes at least one turbine wheel assembly 13 and aturbine shroud assembly 20 positioned to surround the turbine wheelassembly 13 as shown in FIGS. 1 and 2 . The turbine shroud assembly 20is coupled to a case 19 of the gas turbine engine 10. The turbine wheelassembly 13 includes a plurality of blades 15 coupled to a rotor diskfor rotation therewith. The hot, high pressure combustion products fromthe combustor 16 are directed toward the blades 15 of the turbine wheelassemblies 13 along the gas path 17 boundary. The blades 15 are in turnpushed by the combustion products to cause the turbine wheel assembly 13to rotate; thereby, driving the rotating components of the compressor 14and/or the fan 12.

The turbine shroud assembly 20 extends around the turbine wheel assembly13 to block combustion products from passing over the blades 15 withoutpushing the blades 15 to rotate as suggested in FIG. 2 . In theillustrative embodiment, the turbine shroud assembly 20 is made up of anumber of turbine shroud segments 22, one of which is shown in FIGS. 3-7, that extend only partway around the central axis 11 and cooperate tosurround the turbine wheel assembly 13. The turbine shroud segments 22are sealed against one another, such as by strip seal members, toprovide a continuous turbine shroud assembly 20.

Each turbine shroud segment 22 includes the shroud segment 24, thecarrier 26, the retainer system 28 having the bias members 30, 32, andseals 27, 29 as shown in FIGS. 2-7 . The seals 27, 29 are locatedradially between the shroud wall 44 of the shroud segment 24 and thecarrier segment 54 axially forward and aft of the attachment features46, 48 as shown in FIG. 5 . The seals 27, 29 are configured to seal offa cavity 55 of the carrier segment 54 that receives the attachmentfeatures 46, 48.

In the illustrative embodiment, the shroud segment 24 comprises ceramicmatrix composite materials, while the carrier 26 comprises metallicmaterials. In other embodiments, the shroud segment 24, the carrier 26,and the retainer system 28 may each comprise any suitable materialsincluding ceramics, ceramic matrix composites, metals, alloys, superalloys, etc.

The shroud segment 24 includes the shroud wall 44 and the attachmentfeatures 46, 48 as shown in FIGS. 3-7 . Each attachment feature 46, 48includes a base section 70, 71 a first mount post 72, 73, and a secondmount post 74, 75 as shown in FIGS. 4, 6, and 7 . The base section 70,71 extends radially outward from the shroud wall 44. Both the firstmount post 72, 73 and the second mount post 74, 75 extend radiallyoutward form the base section 70, 71. The second mount post 74, 75 isspaced apart circumferentially from the first mount post 72, 73.

The first and second bias members 30, 32 are each locatedcircumferentially between the first and second mount posts 72, 73, 74,75 in the illustrative embodiment. The first bias member 30 is locatedbetween the first mount post 72 and the second mount post 74 of thefirst attachment feature 46. The second bias member 32 is locatedbetween the first mount post 73 and the second mount post 75 of thesecond attachment feature 48.

In the illustrative embodiment, the second mount post 74, 75 is spacedapart circumferentially from the first mount post 72, 73 to define anotch 76, 77 therebetween as shown in FIG. 4 . The first bias member 30is located in the notch 76 between the first and second mount posts 72,74 of the first attachment feature 46 and engages the base section 70.The second bias member 32 is located in the notch 77 between the firstand second mount posts 73, 75 of the second attachment feature 48 andengages the base section 71.

In the illustrative, the first bias member 30 includes features 66, 68to axially locate the first bias member 30 relative to the firstattachment feature 46. The first end 60 of the first bias member 30 isshaped to include a first groove 66, while the second end 62 is shapedto include a second groove 68 as shown in FIG. 4 . The first groove 66receives a portion of the first mount post 72 and the second groove 68receives a portion of the second mount post 73 to block axial movementof the first bias member 30 relative to the shroud segment 24.

In some embodiments, the second bias member 32 includes similar features66, 68. In other embodiments, the carrier 26 may include features toaxially locate the bias members 30, 32 relative to the shroud segment24.

The carrier segment 54 includes an outer wall 80, the first support arm82, and the second support arm 84 as shown in FIGS. 3-5 . The outer wall80 extends circumferentially at least partway about the axis 11. Thefirst or fore support arm 82 extends radially inward from the outer wall80. The second or aft support arm 84 extends radially inward from theouter wall 80. The second support arm 84 is spaced apart axially aftfrom the fore support arm 82 to define the cavity 55 that receives theattachment features 46, 48 of the shroud segment 24.

One pin 56 extends axially into the first support arm 82 of the carriersegment 54, the first mount post 72 of the first attachment feature 46,and the first mount post 73 of the second attachment feature 48. Theother pin 58 is spaced apart circumferentially from the first pin 56.The second pin 58 extends axially into the first support arm 82 of thecarrier segment 54, the second mount post 74 of the first attachmentfeature 46, and the second mount post 75 of the second attachmentfeature 48. Each of the bias members 30, 32 are locatedcircumferentially between the two pins 56, 58.

In the illustrative embodiment, the first and second bias members 30, 32are located radially between the outer wall 80 of the carrier segment 54and the base section 70, 71 of the corresponding attachment feature 46,48 as shown in FIG. 5 . The body 64, 65 of the bias member 30, 32engages the outer wall 80 of the carrier segment 54, while the first andsecond ends 60, 61, 62, 63 engages the attachment feature 46, 48.

In the illustrative embodiment, the carrier segment 54 further includesan axial location feature 96 as shown in FIG. 5 . The axial locationfeature 96 extends radially inward from the outer wall 80 axiallyforward of the second bias member 32. The second support arm 84 and theaxial location feature 96 block axially movement of the second biasmember 32 relative to the shroud segment 24.

In the illustrative embodiment, the first seal 27 is located radiallybetween the first support arm 82 and the shroud wall 44 of the shroudsegment 24. The second seal 29 is located radially between the secondsupport arm 84 and the shroud wall 44 of the shroud segment 24.

A method for assembling the turbine shroud segment 22 may includeseveral steps. Before assembling the shroud segment 24 on the carrier26, the seal 27, 29 are located in channels (not shown) on the first andsecond support arms 82, 84. The first seal 27 is located in the channelon the first support arm 82. The second seal 29 is located in thechannel on the second support arm 84.

With the seals 27, 29 in place, the shroud segment 24 is locatedadjacent to the carrier segment 54 so that the bias members 30, 32 arelocated radially between the radially-inwardly facing surface 81 of thecarrier segment 54 and the radially-outwardly facing surfaces 47, 49 ofthe corresponding attachment feature 46, 48. The shroud segment 24 islocated adjacent to the carrier segment 54 so that the first bias member30 is located radially between the carrier segment 54 and the firstattachment feature 46 and the second bias member 32 is located radiallybetween the carrier segment 54 and the second attachment feature 48.

The bias members 30, 32 may be arranged on the corresponding attachmentfeature 46, 48 before the shroud segment 24 is arranged adjacent to thecarrier segment 54. The attachment features 46, 48 are then insertedinto the cavity 55 so that the pinholes in the attachment features 46,48 align with the corresponding pinholes in the first and second supportarms 82, 84 of the carrier segment 54.

The pins 56, 58 are then inserted axially into the carrier segment 54and the attachment features 46, 48 of the shroud segment 24 to couplethe shroud segment 24 with the carrier segment 54. The first pin 56 isinserted into the second support arm 84 of the carrier segment 54, thefirst mount post 72, 73 of the first and second attachment features 46,48, and the first support arm 82 of the carrier segment 54. The secondpin 58 is inserted into the second support arm 84 of the carrier segment54, the second mount post 74, 75 of the first and second attachmentfeatures 46, 48, and the first support arm 82 of the carrier segment 54.

Once the pins 56, 58 are inserted and the shroud segment 24 is coupledto the carrier segment 54, the bias members 30, 32 apply the bias forceFR to the attachment features 46, 48 of the shroud segment 24. Togetherthe bias members 30, 32 apply the bias force FR to the shroud segment 24in a radial direction to minimize the radial movement of the shroudsegment 24 relative to the carrier 26.

Another embodiment of a turbine shroud segment 222 in accordance withthe present disclosure is shown in FIG. 8-11 . The turbine shroudsegment 222 is substantially similar to the turbine shroud segment 22shown in FIGS. 1-7 and described herein. Accordingly, similar referencenumbers in the 200 series indicate features that are common between theturbine shroud segment 22 and the turbine shroud segment 222. Thedescription of the turbine shroud segment 22 is incorporated byreference to apply to the turbine shroud segment 222, except ininstances when it conflicts with the specific description and thedrawings of the turbine shroud segment 222.

The turbine shroud segment 222 includes a shroud segment 224, a carrier226, seals 227, 229, and a retainer system 228 as shown in FIGS. 8-11 .The shroud segment 224 includes a shroud wall 244 and attachmentfeatures 246, 248 that extend radially outward away from the shroud wall244. The carrier 226 includes a carrier segment 254 and pins 256, 258that extend axially into the carrier segment 254 of the carrier 226 andthe attachment features 246, 248 of the shroud segment 224 to couple theshroud segment 224 to the carrier segment 254. The retainer system 228comprises a plurality of bias members 230, 231, 232, 233 locatedradially between the shroud segment 224 and the carrier 226 so as toapply a bias force FR to the shroud segment 224 to minimize the radialmovement of the shroud segment 224 relative to the carrier 226.

Each of the bias members 230, 231, 232, 233 are axially aligned with oneof the attachment features 246, 248 and circumferentially aligned withone the pins 256, 258 included in the carrier 26 as shown in FIGS. 8-11. The first bias member 230 is axially aligned with the first attachmentfeature 246 and circumferentially aligned with the first pin 256. Thesecond bias member 231 is axially aligned with the second attachmentfeature 248 and circumferentially aligned with the first pin 256. Thethird bias member 232 is axially aligned with the first attachmentfeature 246 and spaced apart circumferentially from the first biasmember 230 so that the third bias member 232 is circumferentiallyaligned with the second pin 258. The fourth bias member 233 is axiallyaligned with the second attachment feature 248 and spaced apartcircumferentially from the second bias member 231 so that the fourthbias member 233 is circumferentially aligned with the second pin 258.

The alignment of the bias members 230, 231, 232, 233 directly above eachof pins 256, 258 applies the bias force FR to the shroud segment 224 atfour different locations. Together the bias members 230, 231, 232, 233apply the bias force FR to the shroud segment 224 in the radialdirection to minimize the radial movement of the shroud segment 24relative to the carrier 26.

In some embodiments, each of the bias member 230, 231, 232, 233 is awave spring. In the illustrative embodiment, the bias members 230, 231,232, 233 are rope seals. In other embodiments, the bias members 230,231, 232, 233 may be a canted coil spring or another bias membersuitable of applying a radial force.

In the illustrative embodiment, each attachment feature 246,248 includesa base section 270, 271 a first mount post 272, 273, and a second mountpost 274, 275 as shown in FIGS. 9-11 . The base section 270, 271 extendsradially outward from the shroud wall 244. Both the first mount post272, 273 and the second mount post 274, 275 extend radially outward formthe base section 270, 271. The second mount post 274, 275 is spacedapart circumferentially from the first mount post 272, 273.

The first bias member 230 is circumferentially aligned with the firstmount post 272 of the first attachment feature 246, while the secondbias third 232 is circumferentially aligned with the second mount post274 of the first attachment feature 246. The second bias member 231 iscircumferentially aligned with the first mount post 273 of the secondattachment feature 248, while the fourth bias member 233 iscircumferentially aligned with the second mount post 275 of the secondattachment feature 248.

In the illustrative embodiment, the bias members 230, 231, 232, 233extend the circumferential length of the corresponding mount post 272,273, 274, 275. Some of the bias members 230, 231, 232, 233 have acircumferential length greater than the other bias members 230, 231,232, 233. In other embodiments, the bias members 230, 231, 232, 233extend part of the circumferential length of the corresponding mountpost 272, 273, 274, 275.

In the illustrative, the carrier segment 254 includes an outer wall 280,the first support arm 282, and the second support arm 284 as shown inFIGS. 8-11 . The outer wall 280 extends circumferentially at leastpartway about the axis 11. The first support arm 282 extends radiallyinward from the outer wall 280. The second support arm 284 is spacedapart axially from the first support arm 282 and extends radially inwardfrom the outer wall 280.

In the illustrative embodiment, the carrier segment 254 further includesaxial location features 296, 297, 298, 299 as shown in FIG. 8 . Theaxial location features 296, 297, 298, 299 extend radially inward fromthe outer radial wall 280 axially forward and aft of each bias member230, 231, 232, 233. The axial location features 296, 297, 298, 299 blockaxially movement of the bias members 230, 231, 232, 233 relative to theshroud segment 224.

The first axial location feature 296 extends radially inward from theouter wall 280 axially forward of the first and second bias members 230,231. The second axial location feature 297 is spaced apart axially fromthe first axial location feature 296 and extends radially inward fromthe outer wall 280 axially aft of the first and second bias members 230,231.

The third axial location feature 298 is spaced apart axially from thefirst and second axial location features 296, 297 and extends radiallyinward from the outer wall 280 axially forward of the third and fourthbias members 232, 233. The fourth axial location feature 299 is spacedapart axially form the third axial location feature 298 and extendsradially inward from the outer wall 280 axially aft of the third andfourth bias members 232, 233.

A method for assembling the turbine shroud segment 222 may includeseveral steps. The shroud segment 224 is located adjacent to the carriersegment 254 so that the bias members 230, 231, 232, 233 are locatedradially between the carrier segment 254 and the attachment features246, 248. The bias members 230, 231, 232, 233 may be arranged on thecorresponding attachment feature 246, 248 before the shroud segment 224is arranged adjacent to the carrier segment 254.

In the illustrative embodiment, the first bias member 230 is arranged onthe first mount post 272 of the first attachment feature 246, while thesecond bias member 231 is arranged on the second mount post 274 of thefirst attachment feature 246. The third bias member 232 is arranged onthe first mount post 273 of the second attachment feature 248, while thefourth bias member 233 is arranged on the second mount post 275 of thesecond attachment feature 248.

The attachment features 246, 248 are then inserted into the cavity 255so that the pinholes in the attachment features 246, 248 align with thecorresponding pinholes in the first and second support arms 282, 284 ofthe carrier segment 254. The pins 256, 258 are then inserted axiallyinto the carrier segment 254 and the attachment features 246, 248 of theshroud segment 224 to couple the shroud segment 224 with the carriersegment 254. Once the pins 256, 258 are inserted and the shroud segment224 is coupled to the carrier segment 254, the bias members 230, 231,232, 233 apply the bias force FR to the attachment features 246, 248 ofthe shroud segment 224.

Another embodiment of a turbine shroud segment 322 in accordance withthe present disclosure is shown in FIGS. 12 and 13 . The turbine shroudsegment 322 is substantially similar to the turbine shroud segment 32shown in FIGS. 1-7 and described herein. Accordingly, similar referencenumbers in the 300 series indicate features that are common between theturbine shroud segment 32 and the turbine shroud segment 322. Thedescription of the turbine shroud segment 32 is incorporated byreference to apply to the turbine shroud segment 322, except ininstances when it conflicts with the specific description and thedrawings of the turbine shroud segment 322.

The turbine shroud segment 322 includes a shroud segment 324, a carrier326, seals 327, 329, and a retainer system 328 as shown in FIGS. 12 and13 . The shroud segment 324 includes a shroud wall 344 and attachmentfeatures 346, 348 that extend radially outward away from the shroud wall344. The carrier 326 includes a carrier segment 354 and pins 356, 358that extend axially into the carrier segment 354 of the carrier 326 andthe attachment features 346, 348 of the shroud segment 324 to couple theshroud segment 324 to the carrier segment 354. The retainer system 328includes bias members 334, 336 configured to apply different bias forcesF₁, F₂, one in the radial and axial direction, the other in only theradial direction.

The retainer system 328 has a first bias member 334 and a second biasmember 336 as shown in FIGS. 12 and 13 . The first and second biasmembers 334, 336 extends at least circumferentially partway about theaxis 11. The first bias member 334 is configured to apply the first biasforce F₁ in the radial and axial directions and a second bias member 336configured to apply the second bias force F₂ in only the radialdirection.

The first bias member 334 is located axially forward of the secondattachment feature 348 and radially between the shroud wall 344 and thecarrier segment 354. The first bias member 334 applies the first biasforce F₁ to the shroud segment 324 in the radial direction to minimizeradial movement of the shroud segment 324 relative to the carriersegment 354 and in the axial direction to axially locate the shroudsegment 324 on an axial location feature 390 included on the carriersegment 354.

The second bias member 336 is located axially forward of the first biasmember 334 and radially between the shroud wall 344 and the carriersegment 354. The second bias member 336 applies the second bias force F₂to the shroud segment 324 in the radial direction to aid the first biasmember 334 in minimizing the radial movement of the shroud segment 324relative to the carrier segment 354.

The carrier segment 354 includes an outer wall 380, a plurality ofsupport arms 382, 384, 386, 388, and the axial location feature 390shown in FIGS. 12 and 13 . The outer wall 380 extends circumferentiallyat least partway about the axis 11. The plurality of support arm 382,384, 386, 388 are spaced apart axially from each other and each extendradially inward from the outer wall 380. Together, the outer wall 380and the support arms 382, 384, 386, 388 form the body of the carriersegment 354.

The plurality of support arms 382, 384, 386, 388 includes a firstsupport arm 382, a second support arm 384, a third support arm 386, anda fourth support arm 388 as shown in FIGS. 12 and 13 . The secondsupport arm 384 is spaced apart axially from the first support arm 382to define a cavity 355. The third and fourth support arms 386, 388extend radially inward from the outer wall 380 axially inbetween thefirst and second support arms 382, 384 to divide the cavity 355 intosections 355A, 355B.

The third support arm 386 is spaced axially aft of the first support arm382 to define a first section 355A of the cavity 355. The firstattachment feature 346 extends into the first section 355A of thecarrier segment 354.

The fourth support arm 388 is spaced axially aft of the third supportarm 386 and axially forward of the second support arm 384 to define asecond section 355B of the cavity 355. The second attachment feature 348extends into the second section 355B of the carrier segment 354.

The fourth support arm 388 includes an engagement surface 392 as shownin FIG. 12 . The first bias member 334 is located between the engagementsurface 392 of the fourth support arm 388 and the shroud wall 344. Theengagement surface 392 is angled or curved and engages the first biasmember 334 to cause the first bias member 334 to urge the shroud segment324 radially and axially. In this way, the first bias force F₁ is inboth the axial and radial directions.

In the illustrative embodiment, the fourth support arm 388 includes theaxial location feature 390 as shown in FIG. 12 . The first bias force F₁applied by the first bias member 334 is configured to bias the secondattachment feature 348 into engagement with the axial location feature390, or chordal seal. The engagement of the second attachment feature348 with the axial location feature 390 helps seal the cavity 355.

The second bias member 336 is located between the third support arm 386and the shroud wall 344. The third support arm 386 may include a curvedsurface 394 that holds the second bias member 336 in place. The curvedsurface 394 engages the second bias member 336 to cause the second biasmember 336 to urge the shroud segment 324 radially such that the secondbias force F₁ is in only the radial direction.

In the illustrative embodiment, the seals 327, 329 are located radiallybetween the shroud wall 344 and first and second support arms 382, 384of the carrier segment 354 axially forward and aft of the attachmentfeatures 346, 348. The bias members 334, 336 are located axially inbetween the attachment features 346, 348.

A method for assembling the turbine shroud segment 322 may includeseveral steps. To begin assembling the turbine shroud segment 322, thefirst bias member 334 is located on a first radially-outwardly facingsurface 345 of the shroud segment 324. The second bias member 336 islocated on the first radially-outwardly facing surface 345 of the shroudsegment 324.

With the bias members 334, 336 in place, the shroud segment 324 islocated adjacent to the carrier segment 354. To locate the shroudsegment 324 adjacent to the carrier segment 354, the attachment features346, 348 are inserted into the respective cavity sections 355A, 355B.

The arrangement of the shroud segment 324 adjacent to the carriersegment 354 locates the bias members 334, 336 radially between thecarrier segment 354 and the first radially-outwardly facing surface 345of the shroud segment 324. The first bias member 334 is located radiallybetween the engagement surface 392 of the fourth support arm 388 and thesecond bias member 336 is located radially between the curved surface394 of the third support arm 386.

Next, the pins 356, 358 are inserted into the carrier segment 354 andthe shroud segment 324 to couple the shroud segment 324 with the carriersegment 354. The first pin 356 is inserted into the carrier segment 354so that the first pin 356 extends axially into the first support arm382, the first attachment feature 346, the third and fourth support arms386, 388, the second attachment feature 348, and the second support arm384.

The second pin 358 is inserted at a location spaced apartcircumferentially from the first pin 356. The second pin 358 is insertedinto the carrier segment 354 so that the second pin 358 extends axiallyinto the first support arm 382, the first attachment feature 346, thethird and fourth support arms 386, 388, the second attachment feature348, and the second support arm 384.

With the shroud segment 324 coupled to the carrier segment 354, thefirst bias member 334 applies the first bias force F₁ to the shroudsegment 324 to minimize radial movement of the shroud segment 324relative to the carrier 326 and to axially locate the shroud segment 324on the axial location feature 390 formed on the carrier segment 354. Thesecond bias member 336 applies the second bias force F₂ to the shroudsegment 324 to aid the first bias member 334 in minimizing the radialmovement of the shroud segment 324 relative to the carrier 326.

Another embodiment of a turbine shroud segment 422 in accordance withthe present disclosure is shown in FIGS. 13 and 14 . The turbine shroudsegment 422 is substantially similar to the turbine shroud segments 22,422 shown in FIGS. 1-7, 12, and 13 and described herein. Accordingly,similar reference numbers in the 400 series indicate features that arecommon between the turbine shroud segments 22, 322 and the turbineshroud segment 422. The description of the turbine shroud segments 22,322 is incorporated by reference to apply to the turbine shroud segment422, except in instances when it conflicts with the specific descriptionand the drawings of the turbine shroud segment 422.

The turbine shroud segment 422 includes a shroud segment 424, a carrier426, and a retainer system 428 as shown in FIGS. 13 and 14 . The shroudsegment 424 includes a shroud wall 444 and attachment features 446, 448that extend radially outward away from the shroud wall 444. The carrier426 includes a carrier segment 454 and pins 456, 458 that extend axiallyinto the carrier segment 454 of the carrier 426 and the attachmentfeatures 446, 448 of the shroud segment 424 to couple the shroud segment424 to the carrier segment 454. The retainer system 428 includes biasmembers 430, 431, 432, 433, 434, 436 that each extends at leastcircumferentially partway about the axis 11 and are configured to applydifferent bias forces F₁, F₂, F₃, F₄, some in the radial and axialdirection, the others in only the radial direction.

The retainer system 428 has two bias members 434, 436 that are eachconfigured to apply a bias force F₁, F₂ in the radial and axialdirections. The other remaining bias members 430, 431, 432, 433 are eachconfigured to apply a bias force F₃, F₄ in only the radial direction.

The first bias member 434 is located axially forward of the aftattachment feature 448 and radially between the shroud wall 444 and thecarrier segment 454. The second bias member 436 is located axiallyforward of the forward attachment feature 446 and radially between theshroud wall 444 and the carrier segment 454. Together the bias members434, 436 apply the first and second bias forces F₁, F₂ to the shroudsegment 424 in the radial direction to minimize radial movement of theshroud segment 424 relative to the carrier segment 454 and in the axialdirection to axially locate the shroud segment 424 on an axial locationfeature 490 included on the carrier segment 454.

The other bias members 430, 431, 432, 433 included in the retainersystem 428 are located radially between the attachment features 446, 448of the shroud segment 424 and the carrier segment 454. The bias members430, 431, 432, 433 apply bias forces F₃, F₄ in only the radial directionto aid in minimizing the radial movement of the shroud segment 424.

The third bias member 430 is located radially between the firstattachment feature 446 of the shroud segment 424 and the carrier segment454 so as to apply a third bias force F₃ to the shroud segment 424. Thefourth bias member 431 is located radially between the second attachmentfeature 448 of the shroud segment 424 and the carrier segment 454 so asto apply a fourth bias force F₄ to the shroud segment 424.

In the illustrative embodiment, each attachment feature 446, 448includes a base section 470, 471 a first mount post 472, 473, and asecond mount post 474, 475 as shown in FIG. 15 . The base section 470,471 extends radially outward from the shroud wall 444. Both the firstmount post 472, 473 and the second mount post 74, 75 extend radiallyoutward form the base section 470, 471. The second mount post 474, 475is spaced apart circumferentially from the first mount post 472, 473.

The third bias member 430 is circumferentially aligned with the firstmount post 472 of the first attachment feature 446, while a fifth biasmember 432 is circumferentially aligned with the second mount post 474of the first attachment feature 446. The fourth bias member 431 iscircumferentially aligned with the first mount post 473 of the secondattachment feature 448, while a sixth bias member 433 iscircumferentially aligned with the second mount post 475 of the secondattachment feature 448.

In the illustrative embodiment, the carrier segment 454 includes anouter wall 480 and a plurality of support arms 482, 484, 486, an axiallocation feature 490 as shown in FIGS. 14 and 15 . The outer wall 480extends circumferentially at least partway about the axis 11. Theplurality of support arm 482, 484, 486 are spaced apart axially fromeach other and each extend radially inward from the outer wall 480.Together, the outer wall 480 and the support arms 482, 484, 486 form thebody of the carrier segment 454. The axial location feature 490 extendsaxially forward from one of the support arms 484 to help axially locatethe shroud segment 424.

The plurality of support arms 482, 484, 486 includes a first support arm482, a second support arm 484, and a third support arm 486 as shown inFIGS. 14 and 15 . The second support arm 484 is spaced apart axiallyfrom the first support arm 482 to define a cavity 455. The third supportarm 486 extends radially inward from the outer wall 480 axially inbetween the first and second support arms 482, 484 to divide the cavity455 into sections 455A, 455B.

The first attachment feature 446 extends into the first section 455A ofthe carrier segment 454. The second attachment feature 448 extends intothe second section 455B of the carrier segment 454. The axial locationfeature 490 extends axially forward from the second support arm 484 andengages the second attachment feature 448 in the illustrativeembodiment.

The third support arm 486 includes an engagement surface 492 as shown inFIG. 14 . The first bias member 434 is located between the engagementsurface 492 of the third support arm 486 and the shroud wall 444. Theengagement surface 492 is angled or curved and engages the first biasmember 434 to cause the first bias member 434 to urge the shroud segment424 radially and axially. In this way, the first bias force F₁ is inboth the axial and radial directions.

The first support arm 482 includes an engagement surface 494 as shown inFIG. 14 . The second bias member 436 is located between the engagementsurface 494 of the first support arm 482 and the shroud wall 444. Theengagement surface 492 is angled or curved like the engagement surfaceof the third support arm 486. The engagement surface 492 engages thesecond bias member 436 to cause the second bias member 436 to urge theshroud segment 424 radially and axially. In this way, the second biasforce F₂ is in both the axial and radial directions.

The axial location features 496, 497, 498, 499 extends radially inwardfrom the outer wall 480 around the corresponding bias members 430, 431,432, 433 as shown in FIG. 14 . The axial location features 496, 497,498, 499 extend radially inward from the outer wall 480 axially forwardand aft of each bias member 430, 431, 432, 433 to block axially movementof the bias members 430, 431, 432, 433 relative to the shroud segment424.

The first axial location feature 496 extends radially inward from theouter wall 480 axially forward of the third and fifth bias members 430,431. The second axial location feature 497 is spaced apart axially fromthe first axial location feature 496 and extends radially inward fromthe outer wall 480 axially aft of the third and fifth bias members 430,431.

The third axial location feature 498 is spaced apart axially from thefirst and second axial location features 496, 497 and extends radiallyinward from the outer wall 480 axially forward of the fourth and fifthbias members 432, 433. The fourth axial location feature 499 is spacedapart axially form the third axial location feature 498 and extendsradially inward from the outer wall 480 axially aft of the fourth andfifth bias members 432, 433.

In the illustrative embodiment, the turbine shroud segment 422 furtherincludes seals 427, 429 as shown in FIG. 14 . The seals 427, 429 arelocated radially between the shroud wall 444 and first and secondsupport arms 482, 484 of the carrier segment 454 axially forward and aftof the attachment features 446, 448. The bias members 434, 436 arelocated axially in between the seals 427, 429.

A method for assembling the turbine shroud segment 422 may includeseveral steps. To begin assembling the turbine shroud segment 422, thefirst bias member 434 is located on a radially-outwardly facing surface445 of the shroud segment 424. The second bias member 436 is located onthe radially-outwardly facing surface 445 of the shroud segment 424. Theremaining bias members 430, 431, 432, 433 may be located axially inbetween the axial location features 496, 497, 498, 499 on the carriersegment 354 or the bias members 430, 431, 432, 433 may be located on theradially-outwardly facing surface of the first and second mount posts472, 473, 474, 475.

With the bias members 430, 431, 432, 433, 434, 436 in place, the shroudsegment 424 is located adjacent to the carrier segment 454. To locatethe shroud segment 424 adjacent to the carrier segment 454, theattachment features 446, 448 are inserted into the respective cavitysections 455A, 455B.

The arrangement of the shroud segment 424 adjacent to the carriersegment 454 locates the bias members 434, 436 radially between thecarrier segment 454 and the shroud segment 424. The first bias member434 is located radially between the engagement surface 492 of the thirdsupport arm 486 and the carrier segment 454. The second bias member 436is located radially between the engagement surface 494 of the firstsupport arm 486 and the carrier segment. The other bias members arelocated radially between the outer wall 480 of the carrier segment 454and the corresponding mount post 472, 473, 474, 475 of the attachmentfeatures 446, 448.

Next, the pins 456, 458 are inserted into the carrier segment 454 andthe shroud segment 424 to couple the shroud segment 424 with the carriersegment 454. The first pin 456 is inserted into the carrier segment 454so that the first pin 456 extends axially into the first support arm482, the first attachment feature 446, the third support arm 486, thesecond attachment feature 448, and the second support arm 484.

The second pin 458 is inserted at a location spaced apartcircumferentially from the first pin 456. The second pin 458 is insertedinto the carrier segment 454 so that the second pin 458 extends axiallyinto the first support arm 482, the first attachment feature 446, thethird support arm 486, the second attachment feature 448, and the secondsupport arm 484.

With the shroud segment 424 coupled to the carrier segment 454, thefirst and second bias members 434, 436 apply the first and second biasforces F₁, F₂ to the shroud segment 424 to minimize radial movement ofthe shroud segment 424 relative to the carrier 426 and to axially locatethe shroud segment 424 on the axial location feature 490 formed on thecarrier segment 454. The third, fourth, fifth, and sixth bias membersapply the third and fourth bias forces F₃, F₄ to the shroud segment 424to aid the first and second bias members 434, 436 in minimizing theradial movement of the shroud segment 424 relative to the carrier 426.

Another embodiment of a turbine shroud segment 522 in accordance withthe present disclosure is shown in FIG. 16-18 . The turbine shroudsegment 522 is substantially similar to the turbine shroud segment 22shown in FIGS. 1-7 and described herein. Accordingly, similar referencenumbers in the 500 series indicate features that are common between theturbine shroud segments 22 and the turbine shroud segment 522. Thedescription of the turbine shroud segments 22 is incorporated byreference to apply to the turbine shroud segment 522, except ininstances when it conflicts with the specific description and thedrawings of the turbine shroud segment 522.

The turbine shroud segment 522 includes a shroud segment 524, a carrier526, and a retainer system 528 as shown in FIGS. 16-18 . The shroudsegment 524 includes a shroud wall 544 and attachment features 546, 548that extend radially outward away from the shroud wall 544. The carrier526 includes a carrier segment 554 and pins 556, 558 that extend axiallyinto the carrier segment 554 of the carrier 526 and the attachmentfeatures 546, 548 of the shroud segment 524 to couple the shroud segment524 to the carrier segment 554. The retainer system 528 includessetscrews 530, 532, 534 threadedly coupled to the carrier segment 554.Each setscrew 530, 532, 534 applies a radial inward force F₁, F₂, F₃ tothe attachment features 546, 548 of the shroud segment 524 to urge theshroud segment 524 radially away from the carrier segment 554 andminimize radial movement of the shroud segment 524 relative to thecarrier 526.

The first and second setscrews 530, 532 engage the first attachmentfeature 546, while the third setscrew 534 engages the second attachmentfeature 548. The second setscrew 532 is spaced apart circumferentiallyfrom the first setscrew 530. The third setscrew 534 is locatedcircumferentially between the first and second setscrews 530, 532 whenthe turbine shroud segment 522 is viewed in the axial direction.

Each of the setscrews 530, 532, 534 have threads 530T, 532T, 534T andare adjustable relative to the carrier segment 554. The setscrews 530,532, 534 may be individually tightened or loosened to adjust theengagement with the shroud segment 524, and thus adjusting the radialinward force F₁, F₂, F₃ applied to the shroud segment 524.

In the illustrative embodiment, the retainer system 528 includes threesetscrews 530, 532, 534 with two setscrews 530, 532 engaged with thefirst attachment feature 546 and other remaining setscrew 534 engagedwith the second attachment feature 548. In other embodiments, two of thesetscrews 530, 532, 534 may be engaged with the second attachmentfeature 548 and other remaining setscrew 530, 532, 534 engaged with thefirst attachment feature 546.

In some embodiments, the retainer system 528 may include more or lessthan three setscrews. In other embodiments, the retainer system 528 mayinclude only two setscrews 530, 523, 534, one setscrew 530, 532, 534engaged with the first attachment feature 546 and the other setscrew530, 532, 534 engaged with the second attachment feature 548.

In the illustrative embodiment, the retainer system 528 further includesa plug 535 as shown in FIGS. 15 and 16 . The plug 535 is locatedradially between the third setscrew 534 and the second attachmentfeature 548 of the shroud segment 524.

In the illustrative embodiment, the plug 535 comprises metallicmaterials. In other embodiments, the plug 535 may be a compliantmaterial or a spring.

The plug 535 includes a radially-inwardly facing surface 537, aradially-outwardly facing surface 539 spaced apart radially from theradially-inwardly facing surface 537, and an outer surface 541 as shownin FIG. 16 . The radially-inwardly facing surface 537 engages the secondattachment feature 548, while the radially-outwardly facing surface 539is engaged by the third setscrew 534. The outer surface 541 extendsbetween and interconnects the surfaces 537, 539. The outer surface 541of the plug 535 slides against a surface 583 of a hole formed in thecarrier segment 554 in the illustrative embodiment.

In the illustrative embodiment, the third setscrew 534 is axially offsetfrom the plug 535 as shown in FIG. 16 . The plug 535 is axially alignedwith the second attachment feature 548, while the third setscrew 534extends into the carrier segment 554 axially forward of the plug 535 andengages the radially-outwardly facing surface 539.

The setscrew 534 is tightened or loosened to slide the plug 535 in holeof the carrier segment 554. As the setscrew 534 pushes on the plug 535,the surface 583 forces the plug 535 to react along the line of action ofthe hole in which the plug 535 slides.

In the illustrative embodiment, each attachment feature 546, 548includes a base section 570, 571 a first mount post 572, 573, and asecond mount post 574, 575 as shown in FIGS. 17 and 18 . The basesection 570, 571 extends radially outward from the shroud wall 544. Boththe first mount post 572, 573 and the second mount post 574, 575 extendradially outward form the base section 570, 571. The second mount post574, 575 is spaced apart circumferentially from the first mount post572, 573.

The first and second setscrews 530, 532 are located circumferentiallybetween the first mount post 572 and second mount post 574 of the firstattachment feature 546 so that the first and second setscrews 530, 532engages the base section 270 of the first attachment feature 546. Thethird setscrew 534 is located circumferentially between the first mountpost 573 and the second mount post 575 of the second attachment feature548 so that the third setscrew 534 engages the base section 271 of thesecond attachment feature 548.

A method for assembling the turbine shroud segment 522 may includeseveral steps. To begin, the shroud segment 524 is located adjacent tothe carrier segment 554. To locate the shroud segment 424 adjacent tothe carrier segment 454, the pin holes formed in the attachment features446, 448 are aligned with pin holes formed in the carrier segment 554.

In some embodiments, before the shroud segment 524 is located adjacentto the carrier segment 554, the plug 535 is inserted into the respectivehole in the carrier segment 554. Once the plug 535 is in place, theshroud segment 524 may be located adjacent to the carrier segment 554 soas to insert the pins 556, 558.

The pins 556, 558 are then inserted axially into the carrier segment 554and the attachment feature 546, 548 of the shroud segment 524 to couplethe shroud segment 524 with the carrier segment 554. With the pins 556,558 inserted, the shroud segment 524 is coupled to the carrier segment554.

Next, the setscrews 530, 532, 534 are threaded into the carrier segment554 to couple the setscrews 530, 532, 534 with the carrier segment 554.Each of the setscrews 530, 532, 534 are then engaged with thecorresponding attachment feature 546, 548 to urge the shroud segmentradially away from the carrier segment and minimize radial movement ofthe shroud segment relative to the carrier.

The first setscrew 530 may be tightened to engage the first attachmentfeature 546 of the shroud segment 524 in between the mount posts 572,574. The second setscrew 532 may be tightened to engage the secondsetscrew 532 with the first attachment feature 546 of the shroud segment524 at a location circumferentially spaced apart from the first setscrew530. The third setscrew 534 may be tightened to engage the secondattachment feature 548 of the shroud segment 524 circumferentially inbetween the mount posts 573, 575.

The present disclosure relates to a method for applying a radial inwardforce or bias force on a ceramic matrix composite shroud segment 24,224, 324, 424, 524. Due to the differential pressure across the shroudsegment 24, 224, 324, 424, 524, the shroud segment 24, 224, 324, 424,524 may chatter due to the blade passing frequency or the blades 15pushing radially outward on the shroud segment 24, 224, 324, 424, 524during a rub event.

The retainer system 28, 228, 328, 428, 528 included in the turbineshroud segment 22, 222, 322, 422, 522 is configured to apply a radialinward force to the shroud segment 24, 224, 324, 424, 524 that mayeither overcome the proposed forces caused by the blades 15 or apply adamping effect that may counter the possibility of rigid body motionthat would otherwise cause chattering.

In the embodiment of FIGS. 1-7 , the retainer system 28 includes twobias members 30, 32. One bias member 30 is located over the first, orforward attachment feature 46 and the other bias member 32 is locatedover the second, or aft attachment feature 48. In the illustrativeembodiment, the first bias member 30 includes grooves 66, 88 that formfingers on the ends 60, 62 of the bias member 30. The fingers extendaround the attachment feature 46 to capture the bias member 30 andmaintain the axial position. The grooves 66, 68 minimize movementaxially while the circumferential size of the bias member 30 blocks thecircumferential movement of the bias member 30. The grooves 66, 68 andfingers may also be applied to the second bias member 32.

In the embodiment of FIGS. 8-11 , the bias members 230, 231, 232, 233are located between the carrier segment 254 and the shroud segment 224directly above the pins 256, 258. The bias members 230, 231, 232, 233may be a wave spring, a rope seal, a canted coil spring, or othersuitable bias member that would apply radial force to the shroud segment224. In the illustrative embodiment, each of the bias members 230, 231,232, 233 are located above one of the mount posts 272, 273, 274, 275.

In the embodiment of FIGS. 12 and 13 , the bias members 334, 336 arelocated between the clevis feature, i.e. the support arms 386, 388 ofthe carrier segment 354, and the shroud segment 324. The bias members334, 336 may be a rope seal, a canted coil spring, or another suitablebias member. The first or aft bias member 334 applies a force in theradial and axial directions. The second bias member 336 applies a forcein only the radial direction.

The bias members 334, 336 may extend circumferentially along the fulllength of the segment 322. The bias members 334, 336 may allow thepressure in the cavity 355 to be varied and reduces the leakage. In theembodiment of FIGS. 14 and 15 , the bias members 434, 436 apply a forcein the radial and axial directions, while the remaining bias members430, 431, 432, 433 apply a force in only the radial direction.

In the embodiment of FIGS. 16-18 , the retainer system 528 includessetscrews 530, 532, 534 that are threaded through the carrier segment554. The setscrews 530, 532, 534 are loaded against the attachmentfeatures 546, 548 of the shroud segment 524 to limit the motion of theshroud segment 524. In some embodiments, the retainer system 528includes a plug 535 that slides relative to the carrier segment 554 andin pushed into engagement with the shroud segment 524 by the thirdsetscrew 534.

While the disclosure has been illustrated and described in detail in theforegoing drawings and description, the same is to be considered asexemplary and not restrictive in character, it being understood thatonly illustrative embodiments thereof have been shown and described andthat all changes and modifications that come within the spirit of thedisclosure are desired to be protected.

1. A turbine shroud assembly for use with a gas turbine engine, theturbine shroud assembly comprising a shroud segment comprising ceramicmatrix composite materials, the shroud segment including a shroud wallthat extends circumferentially partway around an axis to define a gaspath boundary of the turbine shroud assembly and a first attachmentfeature that extends radially outward away from the shroud wall, acarrier comprising metallic materials and configured to support theshroud segment in position radially relative to the axis, the carrierincluding a carrier segment and a pin that extends axially into thecarrier segment of the carrier and the first attachment feature of theshroud segment to couple the shroud segment to the carrier segment, andthe carrier segment having a body and an axial location feature thatextends circumferentially along and axially forward from the body andengages the first attachment feature of the shroud segment, and aretainer system including a first bias member that extendscircumferentially at least partway around the axis, the first biasmember located axially forward of the first attachment feature of theshroud segment and located radially between the shroud wall and thecarrier segment so as to apply a first bias force to the shroud segmentin a radially inward direction to minimize radial movement of the shroudsegment relative to the carrier and in an axially aft direction toaxially locate the shroud segment on the axial location feature of thecarrier segment during use of the turbine shroud assembly.
 2. Theturbine shroud assembly of claim 1, wherein the body of the carriersegment includes an outer wall that extends circumferentially at leastpartway about the axis, a first support arm that extends radially inwardfrom the outer wall, and a second support arm that extends radiallyinward from the outer wall and spaced apart axially from the firstsupport arm to define a cavity that receives the first attachmentfeature of the shroud segment, and wherein the first bias member islocated between the first support arm and the shroud wall.
 3. Theturbine shroud assembly of claim 2, wherein the first support arm isformed to include an engagement surface that engages the first biasmember to cause the first bias member to urge the shroud segment bothradially inward and axially aft.
 4. The turbine shroud assembly of claim2, wherein the retainer system further includes a second bias memberthat extends circumferentially at least partway around the axis, thesecond bias member located radially between the shroud segment and thecarrier segment so as to apply a second bias force to the shroudsegment, and wherein the second bias force applied by the second biasmember is only in the radially inward direction.
 5. The turbine shroudassembly of claim 4, wherein the shroud segment further includes asecond attachment feature spaced apart axially from the first attachmentfeature that extends radially outward away from the shroud wall, the pinextends axially into the carrier segment, the first attachment feature,and the second attachment feature, and the second bias member is spacedaxially forward of the first bias member and axially between the firstand second attachment features.
 6. The turbine shroud assembly of claim4, wherein the shroud segment further includes a second attachmentfeature spaced apart axially from the first attachment feature thatextends radially outward away from the shroud wall, the pin extendsaxially into the carrier segment, the first attachment feature, and thesecond attachment feature, and the second bias member is axially alignedwith one of the first attachment feature and the second attachmentfeature of the shroud segment.
 7. The turbine shroud assembly of claim1, wherein the shroud segment further includes a second attachmentfeature spaced apart axially from the first attachment feature thatextends radially outward away from the shroud wall, the pin extendsaxially into the carrier segment, the first attachment feature, and thesecond attachment feature, and the first bias member is located axiallybetween the first and second attachment features.
 8. The turbine shroudassembly of claim 7, wherein the retainer system further includes asecond bias member that extends circumferentially at least partwayaround the axis, the second bias member located radially between theshroud segment and the carrier segment so as to apply a second biasforce to the shroud segment, and the second bias member is spacedaxially forward of the first bias member and axially between the firstand second attachment features.
 9. The turbine shroud assembly of claim7, wherein the retainer system further includes a second bias memberthat extends circumferentially at least partway around the axis, thesecond bias member spaced axially forward of the second attachmentfeature of the shroud segment and located radially between the shroudsegment and the carrier segment so as to apply a second bias force tothe shroud segment in the radially inward direction and in the axial aftdirection.
 10. The turbine shroud assembly of claim 9, wherein theretainer system further includes a third bias member and a fourth biasmember that each extend circumferentially at least partway around theaxis, the third bias member located radially between the firstattachment feature of the shroud segment and the carrier segment so asto apply a third bias force to the shroud segment, and the fourth biasmember located radially between the second attachment feature of theshroud segment and the carrier segment so as to apply a fourth biasforce to the shroud segment, wherein the third and fourth bias forcesare only in the radially inward direction.
 11. A turbine shroud assemblyfor use with a gas turbine engine, the turbine shroud assemblycomprising a shroud segment including a shroud wall that extendscircumferentially partway around an axis and a first attachment featurethat extends radially outward away from the shroud wall, a carrierincluding a carrier segment and a pin that extends axially into thecarrier segment of the carrier and the first attachment feature of theshroud segment to couple the shroud segment to the carrier segment, anda retainer system including a first bias member that extendscircumferentially at least partway around the axis, the first biasmember located radially and axially between the shroud segment and thecarrier segment and applies a first bias force to the shroud segment ina radially inward direction and an axially aft direction.
 12. Theturbine shroud assembly of claim 11, wherein the carrier segmentincludes an outer wall that extends circumferentially at least partwayabout the axis, a first support arm that extends radially inward fromthe outer wall, and a second support arm that extends radially inwardfrom the outer wall and spaced apart axially from the first support armto define a cavity that receives the first attachment feature of theshroud segment, and wherein the first bias member is located between thefirst support arm and the shroud wall.
 13. The turbine shroud assemblyof claim 12, wherein the retainer system further includes a second biasmember that extends circumferentially at least partway around the axis,the second bias member located radially between the shroud segment andthe carrier segment so as to apply a second bias force to the shroudsegment.
 14. The turbine shroud assembly of claim 13, wherein the shroudsegment further includes a second attachment feature spaced apartaxially from the first attachment feature that extends radially outwardaway from the shroud wall, the pin extends axially into the carriersegment, the first attachment feature, and the second attachmentfeature, and the second bias member is spaced axially forward of thefirst bias member and axially between the first and second attachmentfeatures.
 15. The turbine shroud assembly of claim 11, wherein theshroud segment further includes a second attachment feature spaced apartaxially from the first attachment feature that extends radially outwardaway from the shroud wall, the pin extends axially into the carriersegment, the first attachment feature, and the second attachmentfeature, and the retainer system further includes a second bias memberaxially aligned with one of the first attachment feature and the secondattachment feature of the shroud segment.
 16. The turbine shroudassembly of claim 11, wherein the shroud segment further includes asecond attachment feature spaced apart axially from the first attachmentfeature that extends radially outward away from the shroud wall, the pinextends axially into the carrier segment, the first attachment feature,and the second attachment feature, and the first bias member is locatedaxially between the first and second attachment features.
 17. Theturbine shroud assembly of claim 16, wherein the retainer system furtherincludes a second bias member that extends circumferentially at leastpartway around the axis, the second bias member located radially betweenthe shroud segment and the carrier segment so as to apply a second biasforce to the shroud segment, and the second bias member is spacedaxially forward of the first bias member and axially between the firstand second attachment features.
 18. The turbine shroud assembly of claim16, wherein the retainer system further includes a second bias memberthat extends circumferentially at least partway around the axis, thesecond bias member spaced axially forward of the second attachmentfeature of the shroud segment and located radially between the shroudsegment and the carrier segment so as to apply a second bias force tothe shroud segment in the radially inward direction and the axial aftdirection.
 19. A method comprising providing a shroud segment, acarrier, and a retainer system, the carrier including a carrier segmentand a pin, the retainer system including a first bias member, locatingthe first bias member on a first radially-outwardly facing surface ofthe shroud segment, locating the shroud segment adjacent to the carriersegment so that the first bias member is located radially between thecarrier segment and the first radially-outwardly facing surface of theshroud segment, inserting the pin axially into the carrier segment andthe shroud segment to couple the shroud segment with the carriersegment, and applying a first bias force to the shroud segment in aradially inward direction to minimize radial movement of the shroudsegment relative to the carrier and in an axially aft direction toaxially locate the shroud segment on an axial location feature formed onthe carrier segment.
 20. The method of claim 19, wherein the retainersystem further includes a second bias member and the method furthercomprising locating the second bias member on a secondradially-outwardly facing surface of the shroud segment before locatingthe shroud segment adjacent to the carrier segment so that the secondbias member is located radially between the carrier segment and thesecond radially-outwardly facing surface once the shroud segment islocated adjacent to the carrier segment.